1. Field of the Invention
An aspect of this disclosure relates to an optical module.
2. Description of the Related Art
Electric cables made of, for example, copper have been used for communications of supercomputers and high-end servers via high-speed interfaces. However, optical communication is becoming popular to achieve high-speed signal transmission and to increase the transmission distance.
Next generation interfaces being discussed in standards such as InfiniBand Trade Association Enhanced Data Rate (IBTA EDR (registered trademark)) and 100G Ethernet (registered trademark) have a long transmission distance of tens of meters, and optical communication technologies with optical modules for converting an electric signal to an optical signal are used. For example, an optical module that converts an optical signal into an electric signal and outputs to the server, and converts an electric signal from the server into an optical signal and outputs to the optical cable is used to connect an optical cable and a server.
An optical module may include a light emitter, a light receiver, a driver for driving the emitter, and a trans-impedance amplifier (TIA) for converting an electric current into a voltage (see, for example, Japanese Laid-Open Patent Publication No. 2015-023143). The emitter, the receiver, the driver, and the TIA are mounted on a circuit board in the housing. The emitter and the receiver are connected to a ferrule via a flexible, sheet-shaped optical waveguide.
The circuit board may be misaligned in the housing due to its tolerance in size. This misalignment may cause the optical waveguide, which connects the emitter and the receiver to the ferrule, to warp, and the warp may cause light loss and cause a problem in optical transmission.
For the above reason, there is a demand for a highly-reliable, high-yield optical module whose circuit board can be firmly fixed to a housing at a desired position so as not to cause an optical waveguide to warp.